Integer format specifiers control how integer values are represented by printf(). The length modifiers h, l, and ll specify the expected integer type.

#include <stdio.h>

int main()
{
    int a = -25;
    unsigned int b = 25;
    long c = 100000L;
    long long d = 1000000000LL;

    printf("Decimal       : %d\n", a);
    printf("Unsigned      : %u\n", b);
    printf("Octal         : %o\n", b);
    printf("Hexadecimal   : %x\n", b);
    printf("Long          : %ld\n", c);
    printf("Long long     : %lld\n", d);

    return 0;
}

Example Output #

Decimal       : -25
Unsigned      : 25
Octal         : 31
Hexadecimal   : 19
Long          : 100000
Long long     : 1000000000

Explanation #

The basic integer conversion specifiers are:

For example:

printf("%x\n", b);

prints the value of b in hexadecimal.

Integer Length Modifiers #

Length modifiers can be combined with conversion specifiers:

For printf(), integer types narrower than int, such as short, undergo integer promotion before being passed as arguments. Therefore %hd still corresponds to the promoted argument type expected by printf, with the h modifier controlling how the value is interpreted for output.

The format specifier must match the argument type expected by the conversion specification. A mismatch can result in undefined behavior.